Evaluation of treatment continuation with alosetron by IBS-D severity criteria

Efficacy of the Combination of Pinaverium Bromide 100 mg Plus Simethicone 300 mg in Abdominal Pain and Bloating in Irritable Bowel Syndrome: A Randomized, Placebo-controlled Trial

GOALS

We aimed to evaluate the efficacy and safety of PB+S (pinaverium bromide 100 mg plus simethicone 300 mg) in patients with irritable bowel syndrome (IBS).

BACKGROUND

IBS is a multifactorial disorder; thus, combination therapy with different mechanisms of action is expected to be useful. PB+S has shown effectiveness in an open-label clinical study in IBS. However, there are no placebo-controlled trials.

MATERIALS AND METHODS

IBS-Rome III patients with abdominal pain/discomfort for at least 2 days within the week prior to baseline assessment were included in this 12-week, randomized, double-blind, placebo-controlled study of PB+S versus placebo, bid. The primary endpoint was overall symptom improvement, evaluated weekly by the patient (Likert Scale). Secondary endpoints included the weekly improvement in the severity of abdominal pain and bloating assessed both by patients (10-cm Visual Analogue Scale) and investigators (Likert Scale); frequency of Bristol Scale stool types (consistency) evaluated by patients and the IBS Quality of Life scores.

RESULTS

A total of 285 patients (female: 83%; 36.5±8.9 y old) received at least 1 dose of PB+S (n=140) or placebo (n=145). No difference was observed in overall symptom improvement between the groups (P=0.13). However, PB+S was superior in abdominal pain (effect size: 31%, P=0.038) and bloating (33%, P=0.019). Patients with IBS-C and IBS-M showed the best improvement in the frequency of stool types with PB+S. No differences were observed in IBS Quality of Life scores and adverse events.

CONCLUSIONS

PB+S was superior to placebo in improving abdominal pain and bloating in patients with active IBS. The effect on the frequency of stool consistency was particularly significant in IBS-C and IBS-M.

Rifaximin and eluxadoline - newly approved treatments for diarrhea-predominant irritable bowel syndrome: what is their role in clinical practice alongside alosetron?

INTRODUCTION

Diarrhea-predominant irritable bowel syndrome (IBS-D) is a common functional gastrointestinal condition in which patients experience abdominal pain, diarrhea, bloating, cramps, flatulence, fecal urgency, and incontinence.

AREAS COVERED

We review two recently approved therapies that focus on treating underlying pathogenic mechanisms of IBS-D: (1) the non-absorbable antibiotic rifaximin, and (2) the opioid receptor agonist/antagonist eluxadoline. We compare the safety and efficacy data emerging from rifaximin and eluxadoline registration trials with safety and efficacy data from the alosetron clinical development program.

EXPERT OPINION

The rifaximin and eluxadoline clinical development programs for IBS-D have demonstrated significant improvement in IBS-D endpoints compared to placebo. Direct comparison of primary endpoint results from the alosetron, rifaximin, and eluxadoline pivotal trials is not possible; however, general estimates of efficacy can be made, and these demonstrate similar and significantly greater responses to 'adequate relief' and a composite endpoint of abdominal pain/stool form for each agent compared to placebo. With the recent approval in the United States of rifaximin and eluxadoline for IBS-D, how should clinicians employ these agents? We suggest that they be utilized sequentially, taking into consideration patient symptoms and severity, prior medical history, mode of action, cost, availability, managed care coverage, and adverse event profiles.

A 9-year evaluation of temporal trends in alosetron postmarketing safety under the risk management program

OBJECTIVES

Adverse events (AEs) of ischemic colitis (IC) and complications of constipation (CoC) associated with alosetron are rare and have been adjudicated during the first 5.5 years of the risk management program (RMP); however, changes in incidence rates relative to reductions in AE reports and increases in alosetron prescriptions over the 9-year RMP have not been evaluated. The authors aim to evaluate temporal trends in alosetron postmarketing safety over the 9-year RMP.

METHODS

The alosetron safety database was searched to identify cases of IC, CoC, and related AEs from 20 November 2002 to 31 December 2011. Adjudication of IC and CoC cases were based on US Food and Drug Administration-defined criteria. Incidence rates were calculated using the number of AEs and alosetron prescriptions (expressed as cases/1000 patient-years exposure).

RESULTS

A total of 29 cases were adjudicated as probable/possible IC and 7 cases were adjudicated as CoC. Cumulative adjudicated incidence rate of IC (1.03 cases/1000 patient-years) is low and stable, while that of CoC (0.25 cases/1000 patient-years) is low, declining progressively over time. Decreases in the incidence rates of potential symptoms of IC (abdominal pain with bloody diarrhea/hematochezia) and CoC (constipation) were also observed.

CONCLUSIONS

Over the 9-year RMP period, incidence rates of IC and CoC remain rare. Substantial reductions over time were observed in the incidence of CoC and in symptoms suggestive of IC or CoC, while IC incidence has been stable at approximately 1.0 case/1000 patient-years. Decreases in AEs and serious outcomes associated with IC and CoC since the reintroduction of alosetron are likely attributable to the RMP.